Call flow: Transferring a call on a
BlackBerry device using
Voice over Mobile

A
BlackBerry Mobile Voice System user is on a
BlackBerry device call with Party A using
Voice over Mobile. To transfer the call, the
BlackBerry MVS user presses the Menu key,
clicks Transfer, and clicks the phone number of Party B. When the transfer
process starts, the
BlackBerry MVS puts Party A on hold.

The
BlackBerry MVS Client creates a transfer
request, which includes the destination number. One of the following events
occurs:

If the user is in a
wireless coverage area where data services are not available, the
BlackBerry MVS Client uses DTMF tones to
create the transfer request and sends it to the
MVS Session
Manager.

If the user is in a
wireless coverage area where data services are available, the
BlackBerry MVS Client compresses, encrypts,
and sends the request to the
BlackBerry Enterprise Server over the wireless
network. The
BlackBerry Enterprise Server decrypts,
decompresses, and sends the request to the
MVS BlackBerry Enterprise Server
Connector. The
MVS BlackBerry Enterprise Server
Connector sends the request to the
MVS Session
Manager.

The
MVS Session
Manager sends the
transfer request to the SIP gateway to create a new call through the PBX using the SIP trunk to Party
B.

When Party B answers, the
MVS Session
Manager instructs the SIP gateway to connect the
two call legs. The
BlackBerry MVS user and Party B can
communicate.

The
BlackBerry MVS Client creates a complete
transfer request. One of the following events occurs:

If the user is in a
wireless coverage area where data services are not available, the
BlackBerry MVS Client uses DTMF tones to create the complete transfer request and send it
to the
MVS Session
Manager.

If the user is in a
wireless coverage area where data services are available, the
BlackBerry MVS Client compresses, encrypts,
and sends the request to the
BlackBerry Enterprise Server over the wireless
network. The
BlackBerry Enterprise Server decrypts,
decompresses, and sends the request to the
MVS BlackBerry Enterprise Server
Connector. The
MVS BlackBerry Enterprise Server
Connector sends the request to the
MVS Session
Manager.

The
MVS Session
Manager instructs the SIP gateway to connect Party A to Party B and end the call with the
BlackBerry MVS user's extension number. Party
A can now speak with Party B.

The
MVS Session
Manager instructs the SIP gateway to release the
SIP trunk call leg to the mobile number of the
BlackBerry MVS user.